Re: The Immortalists.
I believe that it is perfectly possible that at some time in the future, perhaps sooner than we think, it will be possible to implant the content of our brains into a machine or, alternatively, to implant our brains as a whole into a machine capable of maintaining the organ.
In the latter case, we already have the beginnings of connecting not only motor and sensory functions of the brain to a machine, but also such senses as sight (retinal chips) and possibly other senses such as hearing, smell and taste. In this scenario, eventually the brain will die just as all organic matter 'wears out' and dies.
In the former case, connecting cameras and microphones and so on, to a machine resembling a computer is already possible, and the final step would be to upload all our memories and consciousnesses to a computer. In this case, mechanical and electronic components can easily be replaced and so could, theoretically, 'live' for ever.
In any event, if this sort of thing does come to pass, we shall be obliged to cease procreating (at least the humans who remain will) or we shall soon become overpopulated. Or perhaps all of the mechanical 'humans' will decide to kill off all of the organic humans. Haven't I watched a film like that?!